There are many instances when it is necessary, during surgery or otherwise, to attach instruments to a frame or support member. For example, during stereotactic surgery, which involves positioning a stable reference point with respect to a patient in order to properly guide and reference instruments to the surgical site, a support member is mounted with respect to a patient, and surgical instruments are positioned with respect to the support member. This invention seeks to provide such a system with a clamp that allows the stable securing of such instruments.
Obtaining clear access to a surgical site during any open surgical procedure presents certain challenges. These challenges are multiplied when the surgical procedure involves precisely locating a specific target location, such as during stereotactic surgery. There is a need for a system that allows retraction of the patient's tissue in order to allow clear access to the site.
The proper location of an endoprosthetic implant is a key element to the success of the implantation procedure in improving patient quality of life. For example, properly locating an intervertebral endoprosthesis ensures, among other benefits, that the patient will enjoy the full range of motion offered by the implant and will avoid potentially dangerous conditions resulting from contact of the implant with delicate spinal cord structures.
The use of intervertebral implants (arthroplasty) has, in recent years, attained increasing acceptance as a preferable alternative to spinal fusion (arthrodesis) as a method for treating patients where discectomy is indicated. This is in part due to recent advances in implant technology, and in part due to the increasing appreciation of the advantages provided by implantation, including increased range of motion, decreased post-operative damage to adjacent intervertebral discs (which can result from the decreased range of motion at the level of the fusion), decreased risk of harvest site morbidity, etc. This increasing acceptance seems likely to continue for the foreseeable future, and more and more implantation procedures will likely be performed.
Similar considerations apply in other areas of surgery, and in particular, in neurosurgery. For example, during surgery on the brain, the surgeon often anchors a frame to the sides of the patient's head, which provides constant reference points during surgery, irrespective of how the patient's head or neck is positioned or moved during the procedure. This level of stereotactic precision in location and placement is particularly desirable for medical and surgical procedures where the margin for error is very small due to the proximity to the spinal cord and other neuro and vascular structures. However, contrary to brain surgery, in most procedures used for spinal surgery, as well as surgery to other body parts, it is difficult to secure an external frame to the patient's skeleton or soft tissues to provide constant reference points.
Electronic systems exist for stereotactic positioning of medical instruments during surgical procedures. However, these systems are extremely expensive, require significant computing power, are highly complex, require specialized software, and are not always available, particularly in smaller health care systems or in less developed countries.
Accordingly, there remains a need in the art for methods and apparatus for locating, and preferably stereotactically locating, targeted implantation positions, for precisely positioning tools for preparing the implantation site, and for precisely inserting the implant in the desired position that is simple, safe, that does not require expensive electronic or computerized tracking of medical instrumentation, and that can be used with conventionally available imaging technologies. Furthermore, there is a need in the art to provide methods and instrumentation that will allow a surgeon to revise two fused vertebra and interpose an articulating implant therebetween.
While current methods may be sufficient to achieve a successful intervertebral implantation, there remains a need for improved techniques and instruments that provide even more precise localization, such as improved stereotactic location of the desired site of the implant, the precision positioning of milling, burring, and other tools and instruments for conducting the procedure, and the implantation of the endoprosthesis into the prepared site.
There remains a further need for a clamping apparatus and method to assist a practitioner in exposing and preparing a cavity to receive an endoprosthesis or any other surgical implant or treatment. In particular, there is a need for a clamp adapted to secure surgical instruments to a stable support frame for the preparation of a surgical site.